Comparison of Disintegration Methods at a Full-scale Anaerobic Digestion Plant
Anke Winter, Johannes A. Müller
Institute
of Sanitary and Environmental Engineering, Technical University of Braunschweig
Pockelsstraße 2a, D-38106 Braunschweig,
Germany
(E-mail: a.winter@tu-bs.de,
jo.mueller@tu-bs.de )
Abstract Various
half-scale and lab-scale investigations have already shown that the
disintegration of excess sludge is a possible pre-treatment to optimise
anaerobic digestion. To verify these results, different methods of
disintegration were investigated at a full-scale plant. Two stirred ball mills,
a plant for oxidation with ozone, a lysate centrifuge and an ultrasonic homogeniser
were applied.
A
positive influence of disintegration on the anaerobic biodegradability could be
established with all aggregates. The enhancement of the degree of degradation
varied between 7.4 to 26 %. Beside this, laboratory investigations proved that
disintegration increases the polymer demand and leads to a lower solid content
after dewatering. Higher ammonia concentrations in the process water after dewatering corroborated the results of
the anaerobic degradation.
Capital costs for the aggregates, costs for energy, manpower and maintenance can be covered, if specific costs for disposal are high. If the development of sludge treatment costs in future and the current discussion about sludge disposal are taken into account, sewage sludge disintegration can be a suitable technique to minimise costs on waste water treatment plants.
Keywords Disintegration,
economic efficiency, full-scale investigations, improvement of stabilisation,
lysate centrifugal technique, ozone treatment, stirred ball mills, ultrasonic
homogeniser
Source: A. Winter, J. A. Müller (2002). Comparison of Disintegration Methods at a Full-scale Anaerobic Digestion Plant, Proceedings of the 7th Latin American Workshop and Symposium on Anaerobic Digestion, Mexico October 2002, 596-602